Data storage tape systems have been used for decades in the computer, audio, and video fields. The data storage tape system includes a tape drive and one or more data storage tape cartridges. During use, storage tape is transferred between a tape reel assembly within the cartridge and a separate tape reel assembly within the drive. In this regard, the storage tape is driven by a tape drive system defined by one or both of the cartridge and tape drive. Regardless of exact form, the data storage tape system continues to be a popular format for recording large volumes of information for subsequent retrieval and use.
With the above in mind, a data storage tape cartridge generally consists of an outer shell or housing maintaining at least one tape reel assembly and a length of magnetic storage tape. A storage tape is wrapped about a hub of the tape reel assembly and is driven through a defined path by a driving system. The housing normally includes a separate cover and a separate base. Together, the cover and the base form an opening (or window) at a forward portion of the housing permitting access to the storage tape by a read/write head upon insertion of the data storage tape cartridge into the tape drive. The interaction between the storage tape and the head can occur within the housing (i.e., a mid tape load design) or exterior to the housing (i.e., a helical drive design). Where the head/storage tape interaction is exterior to the housing, the data storage tape cartridge normally includes a single tape real assembly employing a leader block or similar device. Alternately, where the head/storage tape interaction is within the housing, a dual tape reel configuration is typically employed.
Regardless of the number of tape reel assemblies associated with a particular data storage tape cartridge, the tape reel assembly (also known as a spool) generally includes a hub and one or more reel flanges. In general, the hub includes a core that defines a tape winding surface. The reel flanges are optional, and, if employed, are disposed at opposite ends of the hub and spaced to accommodate a width of the storage tape.
The spool is a repository for the storage tape. In particular, the storage tape is wrapped onto the tape winding surface. In this regard, it is desired that the storage tape be packed onto the hub in a uniform manner. Specifically, edges of the storage tape should be uniformly packed such that the edges are evenly aligned. Significantly, storage tape that is not uniformly packed can be damaged as it traverses the tape drive system. Storage tape that is not uniformly packed is said to have staggered strands. Sources of staggered strands can include non-uniform guiding of the storage tape onto the hub, poor storage tape quality, and aerodynamic forces generated during the winding process. The staggered strands can take several forms, including isolated strands of storage tape that are staggered, popped storage tape strands, and a bulk storage tape stagger where individual popped strands cannot be identified.
Prior art tape winding systems have attempted to uniformly pack storage tape onto hubs. Unfortunately, these prior art tape winding systems do not account for storage tape wear. For example, one prior art tape winding system described in U.S. Pat. No. 6,508,431 employs a tape guide having rigid packing arms. The tape guide is rigidly mounted to a frame by a combination of rigid mounts and fasteners. The rigid packing arms include ceramic plates that contact the edges of the storage tape along an entire radius of the tape pack. In addition, a precisely formed spacer block is utilized to position the rigid packing arms relative to the storage tape, creating a rigid and inflexible tape-packing device. In this regard, the prior art tape guide potentially imparts continuous wear across the storage tape edges.
Another prior art tape winding system, utilizing a flexible packing guide, is described in U.S. Pat. No. 6,045,086. The packing guide is rigidly coupled to a support member. The packing guide employs pleats or corrugations in an attempt to increase the flexibility of the guide, and low friction coatings on a contact edge where the guide touches the film pack. However, the packing guide fails to account for wear imparted to the film that is already uniformly packed about the hub. That is to say, even in the case where the film pack is uniform, the packing guide still imparts a large axial force downward onto the film pack. Despite the presence of the pleats or corrugations, and despite the presence of the low friction coating, the support member splays the packing guide into wear-imparting contact with the film regardless of the uniformity of the film pack.
The winding and unwinding of storage tape from hubs will continue to be an integral step in storing and retrieving data in tape drive systems. With increasing speeds of reading/writing and advanced magnetic tape technology, accurate and consistent storage tape positioning is desirable. To this end, wear imparted to the storage tape as it is packed onto the hub will reduce the life cycle of the storage tape. Therefore, a need exists for a tape drive system capable of uniformly packing storage tape onto the spool with a minimum of storage tape wear.